Fuel tank



April 13, 194s'.

M. M. CUNNINGHAM FUEL TANK/ Filed April 1, 1944 lllllllllllllllllllllllll r1 ATTORNEY y Patented Apr. 13, 1948 UNITED STATE-sA Pirr1-z1srr` FUEL TANK Marion M. (iunnlngham, South Bend, Ind., assignor to UnitedStates Rubber Company, New

York, N. Y., a corporation of New Jersey Application April 1, 1944, Serial No. 529,157

' 2 Claims. (Cl.'154`43.5)

This invention relates to puncture sealingYuel tanks constructed so that holes formed therein by bullets or` other projectiles will close immediately to prevent the escape of fuel,

Fuel tanks, such as puncture sealing fuel tanks for airplanes are usually built accurately to size but so that they Will tightly fit in a` cavity in an airplane, the inner I are usually lslightly less than the corresponding outer dimensions of the fuel tanks. It has, therefore, beencustomary heretofore tomake these puncture sealing fuel tanks with semi-flexible walls so that a tank may be partially collapsed to facilitate Vits insertion in such cavity.

It has been proposed heretofore to improve the puncture sealing properties of a fuel tank by introducing between the semi-flexible walls of such tank and the adjacent metal walls such as the aluminum skin of the airplane, a specially constructed panel formed of extremelystrong and tough sheet material which is stii. These panelsv when introduced between the semi-flexible sidewalls of the fuel tank and the adjacent surround- .ing metal walls such as the aluminum skin of the airplane serve to prevent the metal around a hole produced by a projectile as it enters the ,v tank -from being displaced laterally inwardly ln `the form of ragged projections that may extend into the aligned hole formed in the tank by the projectile and prevent such hole from closing.

dimensions of which cavity Such panel also serves to lessen the displacementv of a tank Wall outwardly by the projectile or thel hydraulic pressure it exerts upon the tankfuel as the projectile forces an exit ,tank Wall. The construction and ruse of such protecting panels are more fully disclosed in the Hoover application, Serial No. 483,457, filed April for Fuel tanks, which application discloses that the stiff protecting panels are cut accurately to the size of the walls of the tank receiving cavity against the metal and are placed in the cavity walls before the tank is introduced into the cavity.

The present invention contemplates a novel construction whereby such stiff protecting panels can be secured directly in the Walls of the puncture sealing fuel tank, and whereby the tank may still be partially collapsed to, facilitate its insertion' in the tank receiving cavity of the airplane, which cavity as above stated is usually slightly smaller' than the outside dimensions of the tank. The primary feature of the present invention resides in-a puncture sealing fuel tank having stiff walls made stii .by such panels and flexible marginal edge portions where the walls join one hole through the panel are exacting to a high '17, 1943, now United States Patent No. 2,429,688,

. j 2 another so that the edges form a hinge-like ilexible connection between the stiff walls. Such a construction is provided by forming a fuel tank with walls of a puncture sealing'- layer of about which there is provided a protecting ,and re-inforcing layer of textile material such as cord fabric, and the tough stili' panelA that improves the puncture sealing properties of the is introduced between the puncture sealing layer and said reinforcing laye The panel, in accordance with the present invention, Vis made somewhat smaller in area than thetank Walls formed by the layers between which the panel is introduced, so that it terminates at the respective edges at'the appro' ate points ywhere the radii of the rounded edges which connect the walls start. As a result of this construction a hingelike flexible connection is provided between the ,stiif tank walls, and the 4paneled walls,` can be forced inwardly or collapsed somewhat so that the tank may be introduced into a slightly smaller cavity. l

By employing the construction of the present invention the stiff tough protecting panels are built into the sidewalls ofthe tank as `an integral structure and are maintained in proper relation with the' puncture Sealing layer of the tank walls. Furthermore this construction facilitates the installation of the tank in the cavity of an airplane since the panels do not haveto be placed separately in such cavity as in the construction of the above-mentioned the panelsare placed in the cavity prior to the introduction of the fuel tank.

The requirements'of the stiif tough protecting degree, since it should not tear or shatter when struck .by a projectile and the projectile when passing therethrough should make a clean'cut hole no larger than the projectile, and the panel should possess these properties throughout a. temperature range from approximately 120 F. above zero to approximately 50 F. below zero'. Also when a projectile enters a fuel tank this panel should supply sufiiowering, and from extending into the aligned hole formed by the projectile in the tank. When the projectile leaves the tank the panel is required toperform a diiferent function, `in that it should now support the tank wall so as to lessen the tendency of the same to be bulged `outwardly under theforce of the draulic bulging force projectilel and the hywhich the conned liquid material fuel tank c Hoover application where I view through a more 4than that shownin Fig. '1; and A the tough panel are incre flexible than exerts upon the tank walls u nder the influence of the projectile.`

The above and other features ofthe. present invention will be-more. fully understood from the following description when read in connec-V tion with the' accompanying-drawing, Awherein Fig. 1 is a perspective View of a fuel tank constructed in laccordance with the present yinvention;

Fie. 2

Fig. 3 is a sectional view of to be described.

The present nvention maybe used in. constructing tanks for gasoline or other fuel, or. for oil tanks and Amay be ous sizes and shapes.' of the-drawing is substantially rectangular in shape and has the stiffened parallel walls III dis-i posed at right angles to each other and these walls are connctedgbylt he rounded edgesA I -I` which the stiifened walls I0..

on a larger scale is -a vertical sectional.

elaborate tank construction employed in tanks of vari-' The tank shown in- Fig. 1vv

. cementform'and'the nylon ir'n bondedto layers I and I6'by cement. The nylon is for the purpose of improving a fuel diffusion resistance I1 is a1 strengthening In carrying out the present'invention all six walls of the tank or if desired fewer-than all sixwalls may have the; stiff, tough panels herein' contemplated associated therewith. The tank shown in Fig. 1 is formed largely of a puncture "This layer I2 may be sealing inner layer I2. formeduof natural or syn hetic rubber which this layer is provided with a protecting coating of synthetic'.rubberlthat-'is capable of resisting face of the .sealant layerv I2 is provided a protect-` ing and reinforcing layer I3 of strong textile material, such forexample .as cord fabric, and

between'these layers I2 and I3 is provided the. stiff, tough panel I4 which panel,- as above stated, is somewhat smaller inarea than the corresponding wall formed ofthe 'layer I2. The construcy eo preferably isunvulcanized and the inner face of the action 'of the tankcontents.V At the outer rubberand the layers 4tire cord.

4 x I5 and I6'are preferably separated .by a lm of nylon which is applied in through rubber `liner I5. and reinforcing `layer of tire cord. I8 isv 'a second laye'r of sealant rubber similar to I6, and' I9 is a second reinforcing layer of tire cord. 2li` is a panel'oftough, stiff protecting material and corresponds to the\panel I4 ofFig. 1.y The layers just described are adhesivelysecuredv together and the entire structure is preferably enclosed by the protecting and 'reinforcing ,layers 2I .and 22 of The' panels I4l and 20 may be constructed as described in the abovementioned Hoover application.'` 'I'he panel 20 as shownin Fig. 3 of the present strong sheets 23 of woven glass fabric which .sheets are bonded togetherand impregnated with a synthetic 'resin 24.

v The re'sin 24 is preferably a synthetic linert thermosetting resin such for example as Laminac P4122 which is described in-the above mentioned.

Hoover application as believedto be a. mixture of alkyd resin and a polymerizableolefln (styrene) i rand is also described onipage 137 of Plastics Catalog, the'1944 Encyclopediaof Plastics,v publishedby Plastic Catalogue Corporation, '122 E.

" .42nd Street, New York, N. Y.

When the stiff tough panel proper position to improve the puncture sealing action, and this'construction makes unnecessary vthework of lining'the walls of thecavity which tion is preferably such 'that the edges of the panel I4 terminate at -approximatelythe starting point of the respective radii ofthe spherical surfaces forming the roundededgesl I as shown in Fig. 1.

As a result of this construction the walls I0 of the receptacle will be quites-tiff throughout the` area thereof occupied by the panel` I4.butwill be 'relatively flexible in the rounded edge portions II where the panel does not extend, whereby the edges' II form a, hinge-like 4flexible lconnection between the much stiffer side walls I0.

The construction is such-that as soon as a projectile pierces the sealant and permits the gasoline or the like to reach the unvulcanized rubber this rubberwill expand toill .the hole.

Also when theprojectile passes from the metal wall surrounding thetank intothe tank the panel I4 will prevent the metal around the projectile` hole from flowering and entering Athe aligned hole in the tank wherel it would prevent the sealant from closing the hole in the layer I2. Furthermore the panel dueto its still.' but resilient properties will yield outwardly momentarily as a projectile passes outwardly therethrough but will immediately force the tank wall back to its planar condition so that the sealant will more effectively close the projectile hole.

Each of the layers I2,` I3, and I4 may be replaced by a-more elaborate ply construction as ,shown in the modification of Fig. 2, and wherein I5 is a lining of synthetic rubber which is not affected by the solvent actionof thefuel such as'gasoline confined in the'tank.- I6 isa layer of sealant rubber such as umiulcanize'ed'synthetic` is to receive the tank before such tank is` placed in thecavity. Having thus described my invention,. what I claim and-desire to protect by Letters Patent is: 1..A selfsealing, non-metallic, fuel tank. for

use in airplanes in close proximity to the metall walls of the airplane, said tank having stiff walls and rounded` flexible marginal edge portions where the walls join one another, each wall being formed of apuncture sealing layer and an outer protecting and reinforcing layer of textile material and having secured between andin contact with these layers a resilient shatter-resistant panel of stiff, tough, high tensile, resin-impregnated woven material through which'alprojectile l will cut a cleanholel and which panelis hard enough to prevent the metal of -a near wall-from v flowering under the impact ofthe projectile through the panel into the wound of theA puncture sealing layer, said panel being somewhat smaller in area than the layers between which it is secured-whereby a paneled wall can be forced bodily inwardly to reduce the size of the tank by bending the less rigid marginal edge portions.

2. A selfsealing, vnon-metallic fuel tank for use in airplanes in close proximity to the` metal walls of the airplane, said tank having stili walls and rounded flexible marginal edge portions where the wal-ls `ioin one another, each wall being formed of a puncture sealing layer and an outer protecting and reinforcing layer of textile materialand having secured between and-in contact with theselayers a resilient shatterresist ant panel of stiff, tough, high tensilematerial formed of .woven'glass cloth impregnated with a syntheticresin and through which a projectile drawing is formed of two extremelyv 'I4 or 20 is embodied fin the wall ofthe tank as hereinfcontemplated the'panel ismaintained finlfcontacting relation with the' inner and outer wa-lls of the tank in will out a clean hole and which panel is hard enough to prevent the metal of a. near wall from owering under the impact of the projectile through the panel into the wound of the puncture sealing layer, said panel being somewhat smaller in area than the layers between which it is secured, whereby a paneled wall can be forced bodily inwardly to reduce the size of the tank by bending the less rigid marginal edge portions.

MARION M. CUNNINGHAM.

REFERENCES CITED The following references are of record in the le o1' this patent:

Number Number UNITED STATES PATENTS Name Date Thacker Mar. 11, 1919 Van Orman Mar. 18, 1928 Pescara Aug. 1, 1944 Crawford Apr. 24, 21945 FOREIGN PATENTS Country Date Great Britain Aug. 2, 1933 

